PMP Mail Archive: Re: PMP> Discussion items for 4/22 Conference call

PMP Mail Archive: Re: PMP> Discussion items for 4/22 Conference call

Re: PMP> Discussion items for 4/22 Conference call

Gail Songer (
Mon, 21 Apr 1997 13:53:16 -0700


I would be happy to add definitions for these words to the FAQ page, but I
don't beleive that we came up with definitions with which the group was happy.
Going back through the discussion, I found the following definitions. Comments
on what the FAQ should actually say?

My initial attempt:

A "door" is something that protects the mechanical insides of a device.

An "interlock" connects two components of a device or two devices. An example
of an interlock is mechanical latch on an optional sorter that connects the
base printer with the sorter.

Don Wright replied:

I would define an interlock as:

A switch or sensor used to stop operation of the device due to the
opening of a door, cover or other component of the device in order
to prevent injury to a human or improper operation of the device.

Bill Wager:

" Cover or Door: The covering to an opening in the printer enclosure
which may be removed or opened to provide access to an area or object
within the printer. A Cover or door open condition may be sensed; if
sensed, the cover open condition may act as an interlock with to
inhibit printer processes or operations which should not be performed
with the cover open."

I would say that an interlock involves sensing a condition as a
prerequisite to allowing some printer operation which might involve
danger, damage, or even just deteriorated quality if the required
condition is not met. An interlock condition could be that a
particular door were closed. But it does not have to be an open door
or even a mechanical irregularity. Some printers would use a toner out
indication to inhibit further printing. This, to me, is also an
interlock since there was no inherent reason why the imaging process
could not be performed. I would even regard a operator's key provision
as an interlock if the key must be in place to print.